1 January 2007

So, what does it mean to reverse diabetes? ‘Rethinking the foods you eat’ says Dr Neal Barnard (physician, clinical researcher, and adjunct associate professor of medicine at the George Washington University School of Medicine). ‘Most people with type 2 diabetes find themselves on a road leading toward gradually increasing weight, slowly rising blood glucose, higher doses of medications and worsening complications.’ It doesn’t have to be that way he says. His research findings, which have been published in peer-reviewed journals (see GI News September 2006), show that people with diabetes can reverse this trend. His vegan program is an aggressive nutritional one, but absolutely achievable as the results clearly show. There are three key guidelines:

Set animal products aside.

Keep vegetable oils to a minimum.

Favour foods with a low GI.

According to Barnard, you’ll find that the side effects are good ones: weight loss, lower cholesterol levels, lower blood pressure, and increased energy. The book sets out his research findings, explains the program he has devised and includes menus and recipes by Bryanna Clark Grogan.For more information on cholesterol, nutrition, meal planning and recipes visit: www.pcrm.org

To be published in the UK in February as The Reverse Diabetes Diet by Rodale International.

This book by the world’s foremost authorities on the glycemic index remains the definitive introduction to and an essential source of new information for anyone wanting to understand the science behind the GI, the health benefits of low GI carbs and how to ‘make the switch’ to low GI eating. This fully revised 3rd US and Canadian edition includes findings from the latest research on GI and weight loss, diabetes, cardiovascular disease and the metabolic syndrome. There are also new chapters on managing PCOS with low GI eating and on vegetarian low GI eating, tables of GI values for more than 500 popular foods, recipes, and answers to nearly 50 of the most frequently asked questions about the GI.

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comments:

I hope you will also review and compare Dr. Richard K. Bernstein's book "Diabetes Solution--the complete guide to achieving normal blood sugars." Dr. Bernstein says just the opposit of Dr Barnard--that fat is an important part of nearly eliminating carbohydrates in order to return to normal blood sugar levels.

So once again, the question is raised, is Dr. Barnard against animal fats because it makes good dietary sense, or because he is secretely pushing an animal rights agenda?

Our recommendations were tested in a randomized clinical trial funded by the U.S. government beginning in 2003. The experimental diet had three components: It was vegan, generally low in fat, and it favored low-GI foods, but did not limit calories, portions, or carbohydrates. Among individuals whose medications remained constant, this regimen led to a drop in A1c of 1.2 percentage points, which was significantly greater than that achieved using a more standard “diabetes diet.” It also led to significant weight loss and a 21 percent drop in the LDL (“bad”) cholesterol. I believe that a low fat intake may work by its ability to reduce intramyocellular lipids, which are believed to be a determinate of insulin resistance.It is hardly a secret that vegan diets are good for the animals and the environment, and it’s well-known that they are also beneficial for cardiovascular health. Our work shows that combining a vegan diet with a reduction in overall fat and a low-GI approach is beneficial for diabetes management. Sincerely, Neal Barnard, M.D.

Our studies have not directly compared a low-fat vegan diet to a low-carbohydrate diet. However, when we compare the results of our studies with those of other investigators using a low-carbohydrate approach, we can make a few observations. For context, it is important to remember that the principal risk in diabetes is cardiovascular damage, which is the combined result of several factors. For the heart, high LDL cholesterol levels, hypertension, smoking, and other factors appear to play larger roles than hyperglycemia. For the microvasculature of the eyes, kidneys, and nerves, hyperglycemia plays a larger role. The bottom line is that we want to control all of these risk factors to the extent we can.

In our recent NIH-funded study, published in Diabetes Care in August, 2006, we found that, in participants whose medications and exercise were held constant, a low-fat, low-GI, vegan diet lowered A1c by 1.2 percentage points on average. Typically you’ll see greater changes among those whose beginning A1c’s were higher or who had a great deal of weight to lose, and smaller changes among those whose A1c values or body weight are lower to start with. We found an average 21% drop in LDL in this group, the LDL/HDL ratio improved, and blood pressure fell somewhat. For further details, readers may wish to consult the original article or the other research details provided in Dr. Neal Barnard’s Program for Reversing Diabetes. For details on beginning such diets, you may wish to visit www.PCRM.org.

Low-carbohydrate diets typically reduce A1c, but have a somewhat unpredictable effect on cholesterol. Weight-loss diets in general ought to reduce cholesterol levels, because weight loss has this beneficial effect. However, with low-carbohydrate diets, this benefit may not arrive. Some people have a cholesterol reduction, while others—about one-third of low-carbohydrate dieters—have a cholesterol increase. In some reports, individuals have had to drop out of low-carbohydrate research studies because of rising LDL. This has been noted by researchers studying low-carbohydrate diets, but so far as I am aware, they have not found an answer to the problem, which seems to stem from the fact that, when carbohydrate-rich foods are limited, some people replace them with meats, dairy products, or other foods that include significant amounts of saturated fat and cholesterol that tend to drive up lipids. Such diets also may contain animal protein, which can be taxing to the kidneys and lead to renal damage over the long run. Happily, some investigators have started to monitor kidney function among low-carbohydrate dieters, although we have no long-term data on their effects in this regard, so far as I am aware.

Some individuals have attempted to combine the two approaches—following low-carbohydrate diets constructed of vegan foods, so as to avoid animal fat and cholesterol and to keep fiber content high. We have not studied that approach. Because populations that follow traditional high-carbohydrate diets (eg, traditional Asian rice-based diets) typically have low rates of diabetes and obesity, and find these rates rising when they abandon rice-based diets in favor of meatier fare, we have taken an interest in the use of plant-based diets.

Some investigators have commented that low-carbohydrate dieters occasionally develop a peculiar sort of irritability. I am not sure whether this relates to a lack of fiber in their diets or to hormonal changes that may come from the use of high-fat, low-fiber regimens. In any case, this may be an added reason for caution.

I plan on looking closely at your diet and research. However, I'm sure you understand that diabetics live by their meter readings

Within minutes, diabetics see the consequences of diet via their BG readings. The same cannot be said for sufferers of CAD. One can eat a certain way for decades without seeing a correlation between diet and heart disease. So a non-diabetic could change to your diet without suffering any short term problems. This cannot be said for a diabetic. Your hi-carb approach could, in the short term, be harmful for a diabetic.

I’m not sure you appreciate that a diabetic’s first priority is to keep BG levels within normal range. You seem to imply that an elevated A1C is ok? Doesn’t the vast body of research point towards the need to keep tight control of BG levels? In particular, aren’t sharp increases in Postprandial BG levels problematic?

Now if your diet is the best approach for diabetics, so be it. I would not hesitate to make the change. I have no agenda other than to live a long and healthy life. But I have to rely on sound science help me with my dietary decisions. I can’t sacrifice health for idealistic beliefs.

I appreciate these comments and questions. But let me be clear: An elevated A1c is not okay, and prolonged elevations of blood glucose are not healthful either. After meals, it is normal for blood glucose to rise, but the rise should be within healthful boundaries, and glucose values should promptly return to lower levels.

It sounds like some readers have not had an opportunity to look at the science behind the use of low-fat, vegan diets for diabetes. We hypothesize that this approach works, not by catering to insulin resistance, as carbohydrate restrictions do, but by repairing insulin resistance, at least to a degree. We suspect that a prime contributor to insulin resistance is the accumulation of microscopic bits of fat in muscle cells. In turn, this fat interferes with insulin signaling. The purpose of a low-fat vegan diet, if I can put it this way, is to help clean that fat out of the cell.

In order to describe this approach and to provide information and tools people might need to put it to work, I wrote a book called Dr. Neal Barnard’s Program for Reversing Diabetes. In it, you will find a summary of studies by my team and others, details on how and why the diet works, easy steps for putting it to work, and plenty of recipes. Let me describe the research basis briefly here:

First, our research was initially based on the consistent finding in epidemiological studies that individuals following diets that are largely plant-based, low in fat, and reasonably high in unrefined complex carbohydrates have a low prevalence of diabetes. Similarly, vegetarians have a lower prevalence of the disease, compared to omnivores.

Studies of near-vegetarian diets, such as those conducted by researchers at the Pritikin center, showed dramatic reductions in blood glucose values in individuals with type 2 diabetes, as well as improvements in cholesterol levels and other health indices. However, these programs also used exercise, making it difficult to draw conclusions about the effect of diet. So, in the mid-1990s, my research group conducted a small pilot study at Georgetown University to test a low-fat, vegan diet for type 2 diabetes, comparing it to a diet following ADA guidelines. The drop in fasting blood glucose values was significantly greater in the vegan group. Weight loss and cholesterol reductions were also impressive (Nicholson A, Preventive Medicine 1999).

We then conducted a trial to focus specifically on weight loss and found that such a diet produced significant weight loss, even in the absence of specified calorie limitations or exercise (Barnard ND, American Journal of Medicine 2005). When we measured insulin sensitivity, we found that it improved significantly in the group following the vegan diet.

Then, in 2003, the U.S. Government funded our group, working with the George Washington University and the University of Toronto, to test a low-fat, vegan diet versus a diet following the 2003 ADA guidelines. As I have noted previously, the drop in A1c was greater in the vegan group, and was similar to that of typical oral diabetes medications. Blood glucose, body weight, plasma lipids, and blood pressure all improved (Barnard ND, Diabetes Care, 2006).

The participants very much enjoyed the diet. A typical menu might consist of a bowl of oatmeal, topped with cinnamon and raisins for breakfast, or perhaps a half cantaloupe or rye toast, followed by a lunch of lentil soup, vegetable stew, or veggie chili with rye bread and vegetables, a snack of fruit, and a dinner of a bean burrito with rice and vegetables, or a veggie burger. Because vegan sources of vitamin B12 (eg, fortified cereals, fortified soymilk, etc.) might not be consumed reliably, a daily multiple vitamin is important as a source of B12.

Many people joining our study were initially a bit fearful of eating beans, sweet potatoes, yams, and oatmeal, because they believed these foods would harm their blood glucose control. Precisely the reverse happened. They improved. They lost weight, their blood glucose and A1c values fell, and their cholesterol levels fell, too. Because the diet does not require counting carbohydrate grams, limiting calories, or measuring portions, many described the diet as much easier than other diets they have tried.

Overall, nutrition improves dramatically on such diets, because they are high in vegetables and fruits, rich in fiber, very low in saturated fat, and essentially devoid of cholesterol.

One note of caution: People beginning any therapeutic diet should speak with their personal physicians before making a diet change. Those who treat their diabetes with insulin or a sulfonylurea and then make a major diet change without adjusting their dosages are very likely to have large reductions in blood glucose and will have hypoglycemic symptoms. While they may be delighted that this is a sign that they are regaining health and that their medications are now too strong for them, it is essential that they understand how to recognize and treat hypoglycemia and that they work with their care-givers to cut back or eliminate medications at the appropriate time.

If you are interested in trying this approach, either for weight loss, for diabetes control, to prevent or reverse heart disease, or to reduce cancer risk, let me invite you to read my books or to visit our Web site, www.PCRM.org, which includes free, noncommercial, online live support groups, a ListServ for questions and answers, and other helpful information.

I hope this information is helpful. If I can answer other questions, I am pleased to do so.

Dear Dr. Barnard:it's interesting to see that vegan diet can improve diabetic control. But I think it's a bit hard to follow for people with celiac disease, as most (if not all) low GI grains contain gluten. So what would be your tips/advice for these people if they want to follow this low GI-vegan diet? Thank you.